Cylinder Texture weird distortion
Smart UV unwrap might work, but this is how I would do it.


make a seam with Ctrl+E along one of the edges of the cylinder.
Select the circle edges with Alt+click (m1 or m2, however you have it set).  Mark that as a seam with Ctrl+E.
Select everything (if your cork is a separate object from the bottle).  Press U to unwrap.  You should get a rectangle and circle in the UV editor, position these how you want.


As a side note, it looks like you have a lot of fireflies.  You may want to follow this article: https://www.blenderguru.com/articles/7-ways-get-rid-fireflies.  In short, use a larger light source and use multiple importance sampling (properties/world/settings).